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transmission/libtransmission/tr-getopt.c
2009-03-17 18:08:02 +00:00

218 lines
5.7 KiB
C

/*
* This file Copyright (C) 2008-2009 Charles Kerr <charles@transmissionbt.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <stdio.h>
#include <stdlib.h> /* exit() */
#include <string.h>
#include "tr-getopt.h"
#ifndef MAX
#define MAX( a, b ) ( ( ( a ) > ( b ) ) ? ( a ) : ( b ) )
#endif
int tr_optind = 1;
static const char*
getArgName( const tr_option * opt )
{
const char * arg;
if( !opt->has_arg )
arg = "";
else if( opt->argName )
arg = opt->argName;
else
arg = "<args>";
return arg;
}
static void
getopts_usage_line( const tr_option * opt,
int longWidth,
int shortWidth,
int argWidth )
{
const char * longName = opt->longName ? opt->longName : "";
const char * shortName = opt->shortName ? opt->shortName : "";
const char * arg = getArgName( opt );
printf( " %s%-*s %s%-*s %-*s %s\n",
(shortName && *shortName ? "-" : " "), shortWidth, shortName,
(longName && *longName ? "--" : " "), longWidth, longName,
argWidth, arg,
opt->description );
}
static void
maxWidth( const struct tr_option * o,
int * longWidth,
int * shortWidth,
int * argWidth )
{
const char * arg;
if( o->longName )
*longWidth = MAX( *longWidth, (int)strlen( o->longName ) );
if( o->shortName )
*shortWidth = MAX( *shortWidth, (int)strlen( o->shortName ) );
if( ( arg = getArgName( o ) ) )
*argWidth = MAX( *argWidth, (int)strlen( arg ) );
}
void
tr_getopt_usage( const char * progName,
const char * description,
const struct tr_option opts[] )
{
int longWidth = 0;
int shortWidth = 0;
int argWidth = 0;
struct tr_option help;
const struct tr_option * o;
for( o = opts; o->val; ++o )
maxWidth( o, &longWidth, &shortWidth, &argWidth );
help.val = -1;
help.longName = "help";
help.description = "Display this help page and exit";
help.shortName = "h";
help.has_arg = 0;
maxWidth( &help, &longWidth, &shortWidth, &argWidth );
if( description == NULL )
description = "Usage: %s [options]";
printf( description, progName );
printf( "\n\nOptions:\n" );
getopts_usage_line( &help, longWidth, shortWidth, argWidth );
for( o = opts; o->val; ++o )
getopts_usage_line( o, longWidth, shortWidth, argWidth );
}
static const tr_option *
findOption( const tr_option * opts,
const char * str,
const char ** setme_arg )
{
size_t matchlen = 0;
const char * arg = NULL;
const tr_option * o;
const tr_option * match = NULL;
/* find the longest matching option */
for( o = opts; o->val; ++o )
{
size_t len = o->longName ? strlen( o->longName ) : 0;
if( ( matchlen < len ) && !memcmp( str, "--", 2 )
&& !memcmp( str + 2, o->longName, len )
&& ( str[len + 2] == '\0' || ( o->has_arg && str[len + 2] == '=' ) ) )
{
matchlen = len;
match = o;
arg = str[len + 2] == '=' ? str + len + 3 : NULL;
}
len = o->shortName ? strlen( o->shortName ) : 0;
if( ( matchlen < len ) && !memcmp( str, "-", 1 )
&& !memcmp( str + 1, o->shortName, len )
&& ( str[len + 1] == '\0' || o->has_arg ) )
{
matchlen = len;
match = o;
switch( str[len + 1] )
{
case '\0':
arg = NULL; break;
case '=':
arg = str + len + 2; break;
default:
arg = str + len + 1; break;
}
}
}
if( setme_arg )
*setme_arg = arg;
return match;
}
int
tr_getopt( const char * usage,
int argc,
const char ** argv,
const tr_option * opts,
const char ** setme_optarg )
{
int i;
const char * arg = NULL;
const tr_option * o = NULL;
*setme_optarg = NULL;
/* handle the builtin 'help' option */
for( i = 1; i < argc; ++i )
{
if( !strcmp( argv[i], "-h" ) || !strcmp( argv[i], "--help" ) )
{
tr_getopt_usage( argv[0], usage, opts );
exit( 0 );
}
}
/* out of options? */
if( argc == 1 || tr_optind >= argc )
return TR_OPT_DONE;
o = findOption( opts, argv[tr_optind], &arg );
if( !o )
{
/* let the user know we got an unknown option... */
*setme_optarg = argv[tr_optind++];
return TR_OPT_UNK;
}
if( !o->has_arg )
{
/* no argument needed for this option, so we're done */
if( arg )
return TR_OPT_ERR;
*setme_optarg = NULL;
++tr_optind;
return o->val;
}
/* option needed an argument, and it was embedded in this string */
if( arg )
{
*setme_optarg = arg;
++tr_optind;
return o->val;
}
/* throw an error if the option needed an argument but didn't get one */
if( ++tr_optind >= argc )
return TR_OPT_ERR;
if( findOption( opts, argv[tr_optind], NULL ) )
return TR_OPT_ERR;
*setme_optarg = argv[tr_optind++];
return o->val;
}